Jay M. Dietrich, Chemical, Environmental and Utility Systems, IBM Burlington, USA
As the semiconductor industry has transitioned from aluminum to copper metallization, it has been necessary to overcome many technical challenges in the device-manufacturing process. The required process changes for the chemical mechanical planarization (CMP) process have had a significant impact on the characteristics of the process wastewaters generated by the CMP process. Organic passivators, chelants, and enhanced slurry formulations have been developed to planarize the copper surfaces to the smoothness required for optimum device performance. In addition, copper is an aquatic toxin and is regulated in the United States both for discharges to municipal wastewater treatment facilities and for discharge directly to receiving waters. These characteristics of the copper CMP wastestream have created difficult challenges in the treatment of wastewaters generated at semiconductor manufacturing facilities.